This invention relates to optical communications networks, and more particularly, to optical equipment for such networks and methods for manufacturing optical equipment.
In optical networks that use wavelength division multiplexing, multiple wavelengths of light are used to support multiple communications channels on a single fiber. Multi-kilometer fiber optic links may be used to interconnect network nodes. The optical equipment that is used in optical networks includes devices such as transmitters, receivers, add/drop modules, routers, and optical amplifiers and other components. The optical equipment may be mounted in racks or other housings at network nodes.
Each optical device typically includes a number of optical components. For example, optical amplifiers typically include components such as wavelength division multiplexing couplers, taps, splitters, laser pumps, filters, and attenuators. These components are typically supplied with fiber pigtails. In fiber amplifiers, lengths of fiber are used to provide optical gain. The lengths of fiber are typically formed into coils for mounting in an amplifier housing. The fiber on each coil is typically many meters in length.
The pigtailed optical amplifier components and fiber are spliced together during the process of assembling the optical amplifier. With conventional optical amplifier housing arrangements, fibers and pigtails may need to be cut to precise lengths before splicing to avoid packaging problems associated with handling fibers and pigtails of different lengths. The process of cutting fibers and pigtails to precise lengths may be time consuming and may make it difficult or impossible to rework defective splices during manufacturing.
It is therefore an object of the present invention to provide optical equipment arrangements and methods for manufacturing optical equipment that facilitate the handling of optical components having fiber pigtails of various lengths.
This and other objects of the invention are accomplished in accordance with the principles of the present invention by providing optical equipment arrangements and methods for manufacturing optical equipment that allow equipment to be fabricated using fiber pigtails of various lengths.
An equipment housing may be provided that has fiber channels. Fibers of various lengths may be produced when the fiber pigtails of optical components are spliced together during manufacturing. The various lengths of fiber may be routed through the fiber channels. Different paths may be taken through the channels to accommodate different fiber lengths.
The equipment housing may include electronics boards for electrical components and an optical tray for mounting optical components with fibers. The optical tray may be formed of a metal or other suitable materials. The fiber channels may be formed as part of the optical tray.
The fiber channel arrangement on the optical tray may involve an oval raceway, component mounting slots, and shortcut paths from the raceway through the component mounting slot area. The shortcut paths may be used to accommodate fibers of different lengths. When optical components are mounted in the component mounting slots, the shortcut path channels guide and protect the fiber pigtails attached to the components.
The component mounting slots may be configured to accommodate either short and wide components or long and narrow components or may be configured to accommodate both short and wide components and long and narrow components.
Overhangs or other suitable protruding portions of the optical tray may be provided in the vicinity of the oval raceway. The overhangs or other protruding portions may be used to help confine optical fiber during and after the assembly process.
Further features of the invention and its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.